ECO STOR GmbH has signed a marketing agreement for its German battery storage project with flexibility marketers Entelios AG from Munich and Enspired GmbH from Vienna, Austria.
The 103.5MW Eco Power One project currently being built in Bollingstedt (Schleswig-Holstein), will be the largest battery storage project in Germany with an installed energy capacity of 238.5MWh and will be connected to the grid from January 2025.
The developer said the partnership combines technological innovation and market-leading expertise to further strengthen the role of battery storage in stabilizing power grids and integrating renewable energy.
Eco Power One is ECO STOR’s first battery storage project of over 100MW and eighth in Germany and represents a further step towards a sustainable energy supply.
As the owner, technical operator and installer of the plant, the company assumes responsibility for all technical and operational aspects.
The location offers both opportunities and challenges: With a high proportion of wind generation in the grid area, it opens up the possibility of making renewable energy available in times of electricity shortages, said the developer.
At the same time, grid fluctuations require targeted measures to stabilise, it added.
The battery storage system plays a central role here by temporarily storing electricity during times of high wind and PV production and feeding it back into the grid in a targeted manner when demand is high.
By participating in balancing reserve markets, the project actively contributes to frequency stability and thus increases security of supply, said ECO STOR.
The company added Entelios and Enspired complement the project with their proven expertise in flexibility marketing.
Entelios, the first demand response provider in Europe, specialises in bundling and marketing flexibility. Through innovative approaches, the company not only contributes to the optimisation of its customers’ energy costs, but also to the security of supply and integration of renewable energies.
Entelios chief executive Fabian Becker said: “Eco Power One is an outstanding example of how the combined expertise of all project partners enables decisive progress for the energy transition.
“With our expertise in flexibility marketing, we are helping to optimally integrate renewable energies into the power grid and at the same time strengthen security of supply in the long term.
“Together with ECO STOR and Enspired, we are setting new standards for the use of large-scale storage systems and creating the basis for a stable and climate-friendly energy future.”
Enspired also takes care of the commercial optimisation of the battery, including fully automated digital infrastructure and high-performance algorithms.
The company specialises in the marketing of flexibilities in the short-term and optimisation in the balancing reserve markets in several European countries.
“Eco Power One impressively demonstrates how technological innovation and digital optimization can go hand in hand to make renewable energies more efficient,” said Enspired chief executive and co-founder Jürgen Mayerhofer.
“Our solutions make it possible to optimally use the flexibility of the battery storage system in short-term and balancing reserve markets, thus making a tangible contribution to grid stability and the energy transition.
Head of Commercial at ECO STOR Stefan Englberger added: “With Entelios and Enspired, we have two outstanding partners at our side who share our vision of a sustainable energy future.
“Their innovative approaches and market knowledge are the key to fully exploiting the project potential of 103.5 MW of flexibility in the German energy markets.”
An important aspect of the Eco Power One project is ecological responsibility, said ECO STOR. The fencing of the facility will be designed to be animal-friendly, and native planting will create new habitats for flora and fauna.
The company added it is thus sending a signal that technological advances and nature conservation can go hand in hand.
The close cooperation with the connection grid operator Schleswig-Holstein Netz GmbH also enables the development of new algorithms that aim to optimise the deployment planning of the project and thus further improve the symbiosis between battery storage systems and renewable energies.
The planned commissioning in January 2025 not only marks the start of plant operation of one of Germany’s most ambitious energy projects, but also sets new standards for the use of large-scale storage systems, said ECO STOR.
In the long term, the project supports the path towards a sustainable energy supply by reducing dependence on fossil energy sources, promoting the integration of renewable energies and making a decisive contribution to reducing CO2 emissions, it added.


